1. Field of the Invention
The present invention relates to digital cable television (hereinafter, referred to as "D-CATV") and video-on-demand (hereinafter, referred to as "VOD") services, and in particular, to an apparatus and method for providing a PC-to-PC (Personal Computer) communication and internet service by using a settop box for D-CATV and VOD services.
2. Description of the Related Art
Digital VOD systems based on the use of existing analog CATV networks and the application of ATM (Asynchronous Transfer Mode) techniques is presently under study. Such a digital VOD system employs an MPEG-2 (Moving Picture Experts Group 2) technique to digitize a video signal, and the ATM technique to distribute the signals. Further, such digital VOD system uses a CATV installation (i.e., coaxial cable or optical cable) to transmit signals between a VOD server and a settop box installed at a user's home. Typically, the modulation-demodulation circuit for the digital VOD system should employ a 64-QAM (Quadrature Amplitude Modulation) modulation, a VBS (Vestigial Side-Band) modulation, and a QPSK (Quadrature Phase Shift Keying) modulation.
The various network access techniques that may be used for the CATV and VOD services are classified as an ADSL (Asymmetric Digital Subscriber Line) network, an HFC (Hybrid Fiber Coax) network, an FTTC (Fiber To The Curb) network, an active NT (Network Terminator) network, and a radio (satellite) access network. The HFC network uses an optical fiber for a trunk line and a coaxial cable for a subscriber line installed at the subscriber's home, based on a frequency multiplexing. The FTTC network uses the optical fiber up to the subscriber's home, and the coaxial or helical pair cable at the subscriber's home, based on a digital transmission. The active NT network terminates the network at the network terminator and distributes the signal within an office or facility.
A settop box that is connected to the FTTC network only provides a digital CATV service. Thus, the settop box for the FTTC network must include an ethernet interface if it is desired to have access to an internet service by using the settop box and a PC. In such case, the PC should also include an ethernet card to provide the ethernet service. This results in a high cost since an operator must maintain ethernet interface cards that are installed at both the settop box and the PC.
Further, in order for the FTTC network to support the internet service, the PC should include an ATM interface card, in addition to the settop box for the D-CATV service, which increases the cost. Moreover, because of the possibility of PC ATM interface card trouble, the operator should also maintain the PC ATM interface card separately.
Conventionally, one may use the PC communication and internet service based on the PSTN (Public Switched Telephone Network) network. In this case, the PC should include a modem, and the internet service is not available while the telephone line is engaged.